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3 years ago

Solve the system of equations.

Mathematics

2 answers:

olga2289 [7]3 years ago

8 0

Answer:

x = 6, y = -3.

Step-by-step explanation:

15x + 31y = -3

x = -y + 3

Substitute x = -y + 3 in the first equation:

15(-y + 3) + 31y = -3

-15y + 45 + 31y = -3

16y = -3 - 45 =-48

y = -3.

So x = -(-3) + 3 = 6.

Alborosie3 years ago

5 0

Answer:

y = - 3, x = 6

Step-by-step explanation:

15x + 31y = - 3

x = - y + 3

15(- y + 3) + 31y = - 3

-15y + 45 + 31y = - 3

16y + 45 = - 3

16y = - 48

y = - 3

x = - (- 3) + 3

x = 3 + 3

x = 6

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3 years ago

A 13-ft ladder is leaning against a house when its base starts to slide away. By the time the base is 5 ft from the house, the

lord [1]

Answer:

a. -5 ft per sec

b. 59.5 ft² per sec

Step-by-step explanation:

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By the Pythagoras theorem,

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$2l\frac{dl}{dt} = 2x \frac{dx}{dt}+2y\frac{dy}{dt}$

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We have,

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Again by equation (1),

$13^2 = x^2 + 5^2\implies 169 = x^2 + 25\implies 169 - 25 = x^2\implies 144 = x^2\implies x = 12\text{ ft}$

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$-120 =24\frac{dx}{dt}$

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